Abstract:

A process for separating at least one tertiary alcohol from at least one
secondary alcohol from pine oil, the process comprising: reacting the
pine oil comprising the at least one secondary alcohol and the at least
one tertiary alcohol with at least one C3-C30 carboxylic acid
ester, and at least one base, wherein the secondary alcohol is esterified
to produce at least one secondary ester, with the proviso that the base
is not a hydroxide; and separating the tertiary alcohol from the
secondary ester.

Claims:

1. A process for separating at least one tertiary alcohol from at least
one secondary alcohol from pine oil, the process comprising:reacting the
pine oil comprising the at least one secondary alcohol and the at least
one tertiary alcohol with at least one C3-C30 carboxylic acid
ester, and at least one base, wherein the secondary alcohol is esterified
to produce at least one secondary ester, with the proviso that the base
is not a hydroxide; andseparating the tertiary alcohol from the secondary
ester.

2. The process of claim 1, wherein the pine oil further comprises water,
and before the pine oil is reacted with the C3-C30 carboxylic
acid ester and the base, the pine oil is treated to substantially remove
the water.

3. The process of claim 1, wherein the secondary alcohol is borneol,
fenchol, or mixtures thereof.

13. The process of claim 1, wherein the tertiary alcohol is separated from
the secondary ester by distillation.

14. The process of claim 1, wherein the process produces at least 95% by
weight of at least one tertiary alcohol.

15. The process of claim 1, wherein the process produces at least 99% by
weight of at least one tertiary alcohol.

16. A process for separating terpineol from borneol and fenchol in pine
oil, the process comprising:treating the pine oil comprising the borneol,
the fenchol, and the terpineol to substantially remove water present in
the pine oil to produce a substantially anhydrous pine oil
mixture;substantially removing the fenchol from the substantially
anhydrous pine oil mixture to produce a borneol and terpineol
mixture;reacting the borneol and terpineol mixture with at least one
C3-C30 carboxylic acid ester and at least one base, wherein the
borneol is esterified to produce a borneol ester, with the proviso that
the base is not a hydroxide; andseparating the terpineol from the borneol
ester.

17. A process for producing fragrance-quality terpineol, the process
comprising:distilling pine oil comprising water, terpenes, fenchol,
borneol, and terpineol to substantially remove the water, the terpenes,
and the fenchol to produce a mixture comprising a majority of borneol and
terpineol;reacting the mixture comprising the majority of the borneol and
the terpineol with at least one C3-C30 carboxylic acid ester
comprising at least one C7-C20 carboxylic acid moiety and at
least one strong organic base, wherein the majority of the borneol is
esterified to produce a borneol ester; anddistilling the terpineol from
the borneol ester, wherein the distilled terpineol comprises at least 95%
by weight of the terpineol.

18. The process of claim 17, wherein the distilled terpineol comprises at
least 99% by weight of the terpineol.

19. The process of claim 17, wherein the distilled terpineol comprises at
least 25% by weight of α-terpineol.

20. The process of claim 17, wherein the distilled terpineol comprises at
least 35% by weight of α-terpineol.

Description:

[0002]Pine oil, which can be derived as an essential oil from Pinus
sylvestris, or alternatively, produced synthetically by acid-catalyzed
reactions of terpenic hydrocarbons, alcohols, or diols in an aqueous
media, comprises a variety of components, including a variety of terpenic
alcohols. Of these terpenic alcohols, terpineol, which is a mixture of
several tertiary alcohol isomers, including α-terpineol,
β-terpineol, γ-terpineol, and 4-terpineol, has a pleasant
floral odor similar to lilac and is widely used in high quality grades in
consumer products in the fragrance and flavor industry. Along with
terpineol, which has a boiling point of approximately 219° C. at
normal pressure, several secondary terpenic alcohols, including fenchol
and borneol which have boiling points of approximately 201° C. and
213° C. at normal pressure, respectively, are present in untreated
pine oil, as well as other constituents, including various other terpenic
alcohols, terpenic carbonyl compounds, terpene hydrocarbons, water, and
other impurities. Separating terpineol from these and other constituents,
as well as other low boiling impurities in pine oil, can be done
relatively effectively and efficiently by employing traditional
separation techniques given the differences in boiling points and
solubilities.

[0003]However, although terpineol can be readily separated from water and
other low boiling constituents in pine oil, terpineol cannot be readily
separated from the secondary alcohols in pine oil, particularly fenchol
and borneol. This is due to all three components having relatively
similar boiling points, which does not allow the components to be
separated easily by traditional separation techniques, particularly
through distillation. Specifically, separating terpineol from borneol is
an especially difficult task, since borneol co-distills with terpineol.
Therefore, in order to sufficiently separate borneol from terpineol,
multiple distillations or multiple other physical separations are usually
required, which are not only time consuming, but are also energy
inefficient, expensive to perform, can create a large amount of waste,
and can denature the original terpineol in the pine oil, thus reducing
the overall terpineol yield. Additionally, in order to produce high grade
quality terpineol for acceptance by the consumer products industry, the
terpineol has to satisfy strict requirements for purity, which is usually
approximately 99% pure, as well as match industry odor standards.
Accordingly, even relatively small amounts of impurities, including
fenchol and borneol, can prevent a batch of terpineol from being
considered high grade quality for use in consumer products.

[0004]Attempts have been made in the past to sufficiently separate the
constituents of pine oil, including the processes outlined in U.S. Pat.
No. 1,980,030, U.S. Pat. No. 2,050,671, and U.S. Pat. No. 1,800,862. In
particular, the process outlined in U.S. Pat. No. 1,980,030 utilizes
ortho-phosphoric acid to react with the terpenic or hydroaromatic
alcohols in pine oil to produce the resultant phosphoric acid addition
compounds. The resultant phosphoric acid addition compounds can then be
separated from the pine oil through extraction, and then saponified back
to the original alcohols. However, although the process of U.S. Pat. No.
1,980,030 generally separates the alcohols present in pine oil from the
non-alcohols, the process does not allow one to separate the individual
alcohols from one another, particularly tertiary alcohols from the other
terpenic alcohols in pine oil.

[0005]With respect to U.S. Pat. No. 2,050,671, the process therein
utilizes boric acid to separate both secondary and tertiary alcohols from
pine oil. In particular, the process of U.S. Pat. No. 2,050,671 reacts
boric acid with the terpenic alcohols in pine oil to produce the
corresponding borates. The borates can then be separated from the pine
oil by distillation, and then saponified back to the original alcohols.
However, as with U.S. Pat. No. 1,980,030, although the process of U.S.
Pat. No. 2,050,671 generally separates terpenic alcohols from
non-alcohols present in pine oil, the process does not allow one to
separate individual alcohols from one another, particularly tertiary
alcohols from the other terpenic alcohols in pine oil.

[0006]As for U.S. Pat. No. 1,800,862, the process therein separates
secondary alcohols from pine oil, including borneol and fenchol. In
particular, the process of U.S. Pat. No. 1,800,862 begins with either
preliminarily fractionating the pine oil to obtain fractions in which the
secondary alcohols are concentrated, thereby removing most of the other
constituents, including terpineol, or dehydrating the pine oil to remove
the terpineol. After the secondary alcohols have been further
concentrated, the secondary alcohols are then esterified with an organic
acid and an acid catalyst, preferably hydrochloric acid, and recovered
through distillation. However, although this process separates the
secondary alcohols from pine oil, the terpineol is irrevocably destroyed
by hydration.

[0007]Therefore, there remains a need in the art for a process to
effectively and efficiently separate tertiary alcohols from the other
constituents in pine oil. In particular, there remains a need in the art
for a process to effectively and efficiently separate tertiary alcohols
from secondary alcohols in pine oil.

SUMMARY OF INVENTION

[0008]The present inventive subject matter generally relates to a novel
process for separating secondary alcohols and tertiary alcohols from pine
oil. In this regard, an embodiment of the present inventive subject
matter relates to a process for separating at least one tertiary alcohol
from at least one secondary alcohol from pine oil, the process
comprising:

[0009]reacting the pine oil comprising the at least one secondary alcohol
and the at least one tertiary alcohol with at least one C3-C30
carboxylic acid ester, and at least one base, wherein the secondary
alcohol is esterified to produce at least one secondary ester, with the
proviso that the base is not a hydroxide; and

[0010]separating the tertiary alcohol from the secondary ester.

[0011]Another embodiment of the present inventive subject matter relates
to a process for separating terpineol from borneol and fenchol in pine
oil, the process comprising:

[0012]treating the pine oil comprising the borneol, the fenchol, and the
terpineol to substantially remove water present in the pine oil to
produce a substantially anhydrous pine oil mixture;

[0013]substantially removing the fenchol from the substantially anhydrous
pine oil mixture to produce a borneol and terpineol mixture;

[0014]reacting the borneol and terpineol mixture with at least one
C3-C30 carboxylic acid ester and at least one base, wherein the
borneol is esterified to produce a borneol ester, with the proviso that
the base is not a hydroxide; and

[0015]separating the terpineol from the borneol ester.

[0016]Additionally, in yet another embodiment, the present inventive
subject matter relates to a process for producing fragrance-quality
terpineol, the process comprising:

[0017]distilling pine oil comprising water, terpenes, fenchol, borneol,
and terpineol to substantially remove the water, the terpenes, and the
fenchol to produce a mixture comprising a majority of borneol and
terpineol;

[0018]reacting the mixture comprising the majority of the borneol and the
terpineol with at least one C3-C30 carboxylic acid ester
comprising at least one C7-C20 carboxylic acid moiety and at
least one strong organic base, wherein the majority of the borneol is
esterified to produce a borneol ester; and

[0019]distilling the terpineol from the borneol ester, wherein the
distilled terpineol comprises at least 95% by weight of the terpineol.

DETAILED DESCRIPTION OF INVENTION

[0020]Definitions:

[0021]As used herein, the phrase "substantially remove", and like phrases,
mean the component being removed is present at less than about 5% by
weight, preferably less than about 1% by weight, and most preferably less
than about 0.5% by weight after being removed.

[0022]As used herein, the phrase "substantially anhydrous", and like
phrases, mean the water content is less than about 1% by weight,
preferably less than about 0.5% by weight, and most preferably less than
about 0.1% by weight after being removed.

[0023]Process:

[0024]The novel process of the present inventive subject matter allows for
the separation of at least one tertiary alcohol from at least one
secondary alcohol from pine oil. In a particular embodiment, the novel
process of the present inventive subject matter relates to a process for
separating at least one tertiary alcohol from at least one secondary
alcohol from pine oil, the process comprising:

[0025]reacting the pine oil comprising the at least one secondary alcohol
and the at least one tertiary alcohol with at least one C3-C30
carboxylic acid ester, and at least one base, wherein the secondary
alcohol is esterified to produce at least one secondary ester, with the
proviso that the base is not a hydroxide; and

[0026]separating the tertiary alcohol from the secondary ester.

[0027]As discussed above, pine oil is composed of a variety of
constituents, including secondary alcohols such as fenchol and borneol,
as well as tertiary alcohols, such as terpineol, which can have high
boiling points within approximately ±18° C. of each other.
Therefore, separating the tertiary alcohols from the secondary alcohols
can often be difficult, time consuming, expensive, and inefficient by
conventional methods, including conventional chemical extraction and
distillation methods. Accordingly, one of the benefits the present
process can provide is a novel process in which tertiary alcohols,
including terpineol, can be separated from pine oil, including separating
the terpineol from the secondary alcohols in pine oil, which include
fenchol, borneol, and mixtures thereof. In a preferred embodiment of the
present process, the terpineol separated from the pine oil can include
α-terpineol, γ-terpineol, and mixtures thereof.

[0028]In a particular embodiment, the process of the present subject
matter separates at least one tertiary alcohol, including terpineol, from
at least one secondary alcohol from pine oil, by reacting the secondary
alcohol in the pine oil with at least one C3-C30 carboxylic
acid ester and at least one base to convert the secondary alcohol into a
corresponding secondary ester, with the proviso that the base is not a
hydroxide, including hydroxides selected from alkali metal hydroxides and
alkali earth metal hydroxides. The tertiary alcohol can then be separated
from the secondary ester in the pine oil by traditional separation
methods, including, but not limited to, distillation with or without
vacuum, and crystallization methods. In a particularly preferred
embodiment, the secondary alcohol in the pine oil can be borneol,
fenchol, and mixtures thereof, and the secondary ester can be borneol
ester, fenchol ester, and mixtures thereof.

[0029]Furthermore, with previous techniques, in order to obtain tertiary
alcohols with sufficient purity from pine oil, multiple traditional
separation methods needed to be performed in order to separate the
tertiary alcohols in pine oil, including terpineol, from the secondary
alcohols in pine oil, including borneol, fenchol, and mixtures thereof.
However, even after performing multiple traditional separations, many
times the resultant tertiary alcohols produced are not of sufficient
purity. Alternatively, preferred embodiments of the present process can
produce at least 95% by weight, and preferably at least 99% by weight of
at least one tertiary alcohol. Additionally, in other preferred
embodiments, the process of the present subject matter can produce a
tertiary alcohol comprising terpineol, wherein the terpineol comprises
25% by weight, and preferably 35% by weight of α-terpineol. In yet
other embodiments of the present process, after the secondary alcohols
are esterified into the corresponding secondary esters, the tertiary
alcohol, including terpineol, can be separated from the secondary ester
by traditional separation methods. In particular embodiments of the
present process, after the secondary alcohols are esterified into the
corresponding secondary esters, the tertiary alcohol, including
terpineol, can be separated from the secondary ester in a single
separation step or multiple separate steps, including but not limited to,
a single distillation or multiple distillations.

[0030]Pine Oil:

[0031]In addition to the benefits discussed above, another benefit the
present process can have is that any type of pine oil can be used,
including "crude" (i.e., untreated) pine oil, or pre-treated pine oil,
and the pine oil can be derived from natural sources such as Pinus
sylvestris, or derived synthetically. Crude pine oil can generally have a
starting tertiary alcohol content, including terpineol, ranging from
about 20% to about 80% by weight, with the remaining content being
composed of various impurities, including, but not limited to, water,
other terpenic alcohols, including secondary terpenic alcohols such as
fenchol and borneol, terpenic carbonyl compounds, pinenes, pinanols, and
terpene hydrocarbons. In particular embodiments of the present process,
crude pine oil which has not undergone any pretreatment can be used.

[0032]Alternatively, in other embodiments of the present process,
pre-treated pine oil can be used, wherein the pre-treated pine oil can
generally have a higher or lower tertiary alcohol content, including
generally a higher or lower terpineol content than that of crude pine
oil. In particular, the pine oil used in the present process can be
treated in a variety of ways before use, including but not limited to,
treating the pine oil before use by separating various components from
the pine oil, including lower boiling impurities. Generally, components
having a boiling point lower than approximately 200° C. at normal
pressure, including water and low boiling impurities, can be separated
before using the pine oil in the present process in a variety of ways,
including separation processes utilizing differences in boiling points,
including but not limited to distillation with or without a vacuum,
differences in crystallization, differences in solubilites, and
differences in polarity, which are well-known in the art. Examples of
separation processes can be found in the Kirk-Othmer Encyclopedia of
Chemical Technology, 5th edition, published by John Wiley & Sons.

[0033]Additionally, in particularly preferred embodiments of the present
process, the pine oil can be pre-treated to substantially remove any
number of various impurities, including, but not limited to, water,
terpenic carbonyl compounds, pinenes, pinanols, and terpene hydrocarbons.
Furthermore, in particular preferred embodiments of the present process,
the pine oil can be treated to substantially remove at least the water
present in the pine oil before being used. Additionally, in other
particular preferred embodiments of the present process, the pine oil can
be pre-treated to substantially remove the impurities previously
mentioned, as well as various terpenic alcohols, including, but not
limited to fenchol.

[0034]In embodiments in which the pine oil is treated to substantially
remove the water present in the pine oil before the process is carried
out, the amount of water substantially removed can be, but is not
required to be, such that the resultant treated pine oil is substantially
anhydrous. In yet another embodiment of the present process, the pine oil
is treated to substantially remove at least the water and the fenchol
present before the pine oil is used. Furthermore, in yet another
embodiment of the present process, the pine oil is treated to
substantially remove at least the water, the terpenes, and the fenchol
present before the pine oil is used. Moreover, in particular preferred
embodiments of the present process, crude pine oil can be pre-treated to
remove a front cut of the pine oil with boiling temperatures up to about
201° C. at normal pressure, wherein the front cut is composed of
various lower boiling impurities, including, but not limited to water,
terpenic carbonyl compounds, pinenes, pinanols, terpene hydrocarbons, and
fenchol. Accordingly, when a front cut with boiling temperatures up to
about 201° C. at normal pressure is removed from the pine oil, the
resultant mixture comprises a majority of terpineol and borneol. The
resultant mixture comprising a majority of terpineol and borneol can then
be reacted with at least one C3-C30 carboxylic acid ester and
at least one base to produce a mixture comprising terpineol and at least
one borneol ester, with the proviso that the base is not a hydroxide,
including hydroxides selected from alkali metal hydroxides and alkali
earth metal hydroxides, with the terpineol then being separated from the
borneol ester.

[0035]However, regardless of whether the pine oil used in the present
process is crude pine oil or pre-treated pine oil, whether the pine oil
is derived from natural sources or produced synthetically, as well as
regardless to the amount of tertiary alcohol and terpineol content in the
pine oil used, one of the benefits of the present process is that the
process can separate the tertiary alcohols, including terpineol, from the
secondary alcohols present in the pine oil.

[0036]Carboxylic Acid Ester:

[0037]The carboxylic acid esters useful for the present process are those
that can react with a secondary alcohol in the presence of a base to
produce a corresponding secondary ester. Accordingly, various carboxylic
acid esters can be used with the present process, including using a
single carboxylic acid ester, or a mixture of various carboxylic acid
esters, with the carboxylic acid esters including monobasic, dibasic,
polybasic carboxylic acid esters, or mixtures thereof.

[0038]Generally, the carboxylic acid esters useful for the present process
can be at least one C3-C30 carboxylic acid ester comprising a
C2-C20 carboxylic acid derived moiety, and a C1-C10
alcohol derived moiety. In preferred embodiments of the present process,
the carboxylic acid ester used can be at least one C8-C25
carboxylic acid ester comprising a C7-C20 carboxylic acid
derived moiety, and a C1-C5 alcohol derived moiety, and in
particularly preferred embodiments of the present process, the carboxylic
acid ester can be at least one C8-C23 carboxylic acid ester
comprising a C7-C20 carboxylic acid derived moiety, and a
C1-C3 alcohol derived moiety.

[0039]Alternatively, carboxylic acid esters of the tertiary alcohols being
separated can be used in the present process. In this regard, preferred
carboxylic acid esters can include terpineol carboxylic acid esters.

[0041]The amount of carboxylic acid ester or esters used in the present
process can be dependent upon the type of pine oil used. In particular,
if crude pine oil is used, then generally a larger amount of at least one
carboxylic acid ester can be used. Alternatively, if pre-treated pine oil
is used, especially pine oil which has been pre-treated to separate a
front cut with boiling temperatures up to about 201° C. at normal
pressure, then generally a lesser amount of at least one carboxylic acid
ester can be used. In general, the amount of the carboxylic acid ester or
esters used is dependent upon the concentration of secondary alcohols
present in the pine oil to be subjected to the present process.
Therefore, the higher the concentration of secondary alcohols in the pine
oil to be treated, the greater the amount of at least one carboxylic acid
ester should be used. Contrastingly, the lower the concentration of the
secondary alcohols in the pine oil to be treated, the lesser the amount
of at least one carboxylic acid ester should be used. Preferably, the
molar concentration of carboxylic acid ester or esters used to the molar
concentration of secondary alcohols in the pine oil can be approximately
1:1.5 to 10:1. However, regardless of the concentration of secondary
alcohols present in the pine oil used in the present process, at least
one carboxylic acid ester can be added in any amount, including but not
limited to, an amount in excess.

[0042]In this regard, in preferred embodiments of the present process, at
least one C3-C30 carboxylic acid ester is added to pine oil
with a base, wherein the C3-C30 carboxylic acid esterifies at
least one secondary alcohol in the pine oil to produce a secondary ester.
In particularly preferred embodiments of the present process, at least
one C3-C30 carboxylic acid ester is added to pine oil, the pine
oil comprising at least a mixture of terpineol and borneol, wherein the
C3-C30 carboxylic acid ester esterifies a majority of the
borneol into a corresponding borneol ester. Additionally, in yet further
particularly preferred embodiments of the present process, at least one
C3-C30 carboxylic acid ester is added to pine oil, the pine oil
comprising at least a mixture of terpineol, borneol, and fenchol, wherein
the C3-C30 carboxylic acid ester esterifies a majority of the
borneol and fenchol into at least one corresponding borneol ester and at
least one fenchol ester.

[0043]Base:

[0044]The bases useful for the present process are those that can
facilitate a reaction between a secondary alcohol and a carboxylic acid
ester, with the proviso that the base is not a hydroxide, including
hydroxides selected from alkali metal hydroxides and alkali earth metal
hydroxides. Therefore, various bases can be used with the present
process, including the use of a single base, as well as a mixture of
bases. Generally, the bases useful for the present process can be at
least one strong base capable of establishing an equilibrium between
reactants, with the base or bases comprising a pKa of the corresponding
conjugate acid greater than about 9, more preferably greater than about
15. In preferred embodiments of the present process, the base or mixture
of bases can comprise a pKa ranging from about 9 to about 40, and
preferably from about 15 to about 25.

[0047]Alternatively, in other particular embodiments of the present
process, the base can be at least one inorganic base, preferably a strong
inorganic base, with the proviso that the base is not a hydroxide,
including hydroxides selected from alkali metal hydroxides and alkali
earth metal hydroxides. Preferred inorganic bases include sodium oxide,
potassium oxide, calcium oxide, magnesium oxide, sodium hydride, sodium
amide, sodium carbonate, potassium carbonate, cesium carbonate, metallic
sodium, and mixtures thereof. Furthermore, ion-exchange resins such as
Amberlite® ion-exchange resins, including but not limited to
Amberlite® IRA-67, can also be used alone or in conjugation with other
bases.

[0048]The amount of base or bases used in the present process can be
dependent upon the type of pine oil used. In particular, as with the
amount of carboxylic acid ester or esters used, if crude pine oil is
used, then generally a larger amount of at least one base can be used.
Additionally, since water may denature the base, the higher the water
concentration is in the pine oil, the more base may be needed.
Alternatively, if pre-treated pine oil is used, especially pine oil which
has been pre-treated to separate a front cut with boiling temperatures up
to about 201° C. at normal pressure, then generally a lesser
amount of at least one base can be used. In general, the amount of base
used can be dependent upon the concentration of water present in the pine
oil, the relative strength and concentration of the base or bases used,
and the concentration of secondary alcohols in the pine oil. Therefore,
preferably, the molar concentration of the base or bases used to the
molar concentration of secondary alcohols in the pine oil can be
approximately about 1:1 to about 1:20, more preferably about 1:3 to about
1:10.

[0049]Alternatively, in additional embodiments of the present process, at
least one base can be used in excess. However, if at least one base is
used in excess, in preferred embodiments of the present process, the
excess base is substantially neutralized before the tertiary alcohol is
separated from the pine oil. Accordingly, if at least one base is used in
excess, in a preferred embodiment of the present process, the excess base
is neutralized such that the pine oil comprises a pH less than about 9,
preferably less than about 8, and most preferably the pine oil comprises
a pH ranging from about 4 to about 8.

EXAMPLES

[0050]The following examples are illustrative of preferred compositions,
and are not intended to be limitations thereon. All product composition
percentages are based on totals equal to 100% by gas chromatography
analysis, and yield percentages are based on totals equal to 100% by
weight, unless otherwise specified.

[0051]Test Methods:

[0052]Purity and composition percentages were determined using gas
chromatography without a solvent on a 30-meter capillary column with a
SPB-1 stationary phase on an Agilent Technologies 6890N GC.

[0053]Odor evaluations were performed by a panel of trained professionals
comparing the odor profile and quality of compositions obtained against
the odor and quality industry standard for terpineol.

[0062]Crude pine oil (3865 g; GC: terpineol: 63.9%; fenchol: 8.06%;
borneol: 2.34%) is distilled on 4' column at 10-20 mm Hg with a split
ratio (R:R) of 40:8, corresponding to a take-off rate of 80.5 g/hr, to
give 17 cuts. A blend of cuts 14-17 cuts (850 g) has a satisfactory GC
analysis (terpineol: 99.1%; fenchol: 0%; borneol: 0.73%), but the yield
is too low (22 wt. %). Moreover, its odor does not match that of the
industry standard. This example shows that a single distillation of crude
pine oil is inefficient for producing high-quality terpineol.

Comparative Example 2

Crude Pine Oil Distillation without Carboxylic Acid Ester and Base

[0063]Crude pine oil (1697.2 g; GC: terpineol: 62.1%; fenchol: 7.85%;
borneol: 2.4%) is distilled on 4' column at 10-20 mm Hg with a split
ratio (R:R) of 40:6, corresponding to a take-off rate of 57.2 g/hr, to
give 17 cuts. A blend of cuts 12-17 cuts (550.2 g) has a satisfactory GC
analysis (terpineol: 99.14%; fenchol: 0%; borneol: 0.68%), but even with
the slower take-off rate, the yield is too low (32.4 wt. %). Moreover,
its odor does not match that of the industry standard. This example shows
that even a slower and longer single distillation of crude pine oil is
inefficient for producing high-quality terpineol.

Comparative Example 3

Crude Pine Oil Distillation with Sodium Hydroxide

[0064]A mixture of crude pine oil (100 g, dehydrated by distillation),
ME-1095 fatty acid methyl ester mixture (6.0 g, product of Peter Cramer
NA, LP), and a solution of sodium hydroxide (1.1 g) in methanol (10 g) is
kept at 110° C., 30 mm Hg with stirring for 140 min. About
two-thirds of the ME-1095 reacts with NaOH to produce sodium salts of
fatty acids, and only 0.06% of the corresponding esters form. This
example shows that sodium hydroxide is an inefficient catalyst for the
disclosed esterification reaction.

[0066]The present subject matter being thus described, it will be apparent
that the same may be modified or varied in many ways. Such modifications
and variations are not to be regarded as a departure from the spirit and
scope of the present subject matter, and all such modifications and
variations are intended to be included within the scope of the following
claims.